• Food Science and Biotechnology
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• 제16권5호
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• pp.722-727
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• 2007

Mucilage containing ${\gamma}-polyglutamic$ acid (PGA) was efficiently generated by the solid-state fermentation (SSF) of soybean grit by Bacillus firmus NA-1. B. firmus NA-1 was shown to be a glutamate-dependent strain for PGA production. The SSF of soybean grit was optimized in order to produce mucilage with a fortification of 5% glutamate, resulting in higher levels of mucilage production (6.14%) and a higher consistency index ($1.1\;Pa\;sec^n$). The sticky mucilage was comprised of 38% PGA, 7% levan, and some biopolymers. With regard to the viscoelastic properties of the mucilage solution, the viscous modulus (G") obtained from soybean grit fortified with 5% glutamate was approximately 64 times higher titan that of the mucilage solution obtained without glutamate. Although the addition of glutamate in the SSF of soybean grit influenced the rate of PGA production, the molecular weight of PGA remained unaltered, and was detected in a range between 1,400-1,440 kDa.

• Korean Chemical Engineering Research
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• 제49권4호
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• pp.475-479
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• 2011

키토산은 천연고분자 물질로 다양한 물리화학적(다중양이온, 반응성 수산화기와 아미노기 그룹), 생물학적(생리활성, 생체적합성, 생분해성) 특성을 가지고 있다. 본 연구에서는 겔형성제로 폴리감마글루탐산을 이용하여 키토산 나노입자를 제조하였다. 나노입자는 폴리감마글루탐산의 카르복실기($-COO^-$)와 키토산의 아미노기($-NH_3^+$)사이의 이온 상호작용에 의해 형성되었다. 키토산(0.1~1 g)을 100 ml 아세트산 용액(1% v/v)에 첨가한 후 상온에서 충분히 용해되도록 하룻밤 동안 교반하였다. 폴리감마글루탐산(0.1 g)은 상온에서 90 ml 증류수에 용해시켰다. 교반되고 있는 폴리감마글루탐산 용액에 키토산 용액을 주사바늘을 통해 상온에서 적가하였다. 입자의 평균 크기는 80~300 nm 범위에서 형성되었다. 키토산/폴리감마글루탐산 나노입자는 중금속 이온들($Cd^{2+}$, $Pb^{2+}$, $Zn^{2+}$, $Cu^{2+}$, $Ni^{2+}$)의 제거를 위해 콜로이드 상태의 흡착 물질로 사용되었다. 나노입자의 중금속 제거 능력은 $Cu^{2+}$ > $Pb^{2+}$ > $Cd^{2+}$ > $Ni^{2+}$ > $Zn^{2+}$의 결과를 보였다.

• 생명과학회지
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• 제16권2호
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• pp.175-179
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• 2006

폴리감마글루탐산(PGA)을 대량생산하는 균주를 축분퇴비에서 분리하고 생리 생화학적 특징 및 16s rRNA 염기서열을 분석한 결과, Bacillus subtilis로 동정하고 strain CH-10 으로 명명하였다. PGA 생산을 위한 배지의 최적 온도와 pH는 각각 $37^{\circ}C$, 7.5 이었다. 또한 배지성분 중에서 PGA 생산에 최적인 탄소원과 질소원은 각각 5% sucrose와 3% L-glutamate인 것으로 나타났다. 이 균주는 L-glutamate에 의해 PGA 생산이 대량으로 유도되었고 따라서 질소원으로 L-glutamate를 반드시 필요로 하는 glutamate 의존성 균주인 것으로 사료되었다. 배양시간에 따라 생산된 PGA의 생화학적 특정을 SDS-PAGE와 ninhydrin 분석을 통하여 검토하였다. PGA의 생산량은 배양시간에 따라 증가하였고 배양 후 96시간에서 최고 생산량을 나타내었다, 생산된 PGA의 평균분자량을 FDNB법으로 분석한 결과, 1,100 kDa인 것으로 나타났다.

• Journal of Microbiology and Biotechnology
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• 제25권7호
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• pp.1163-1169
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• 2015

Poly-gamma-glutamic acid (γ-PGA) is a natural polymer that is synthesized by Bacillus species and has been reported to have antitumor activity. The aim of this study was to investigate the effect of γ-PGA on the treatment of vaginal intraepithelial neoplasia (VAIN). A retrospective observational study on γ-PGA therapy for biopsy-proven VAIN was conducted. The efficacy was assessed by evaluating the results of Pap cytology and the viral load of high-risk HPV at three time points: at enrollment, and at the first and second post-treatment visits. Of 17 patients treated with γ-PGA, only 12 patients who had a high-risk HPV infection were included in the analysis. Histology was VAIN1 in seven patients, VAIN2 in two patients, and VAIN3 in three patients. γ-PGA was administered for newly diagnosed VAIN in five (41.7%) patients and persistent VAIN in seven (58.3%) patients for the mean time of 4.5 months. At the first and second post-treatment visits, cytological regression was observed in five (41.7%) and six (50%) patients, respectively. Regarding the HPV load, the overall response rate was 66.7%, and the mean level was 670.6 ± 292.5 RLU at the first follow-up, which was lower than the initial viral load of 1,494.8 ± 434.5 RLU (p = 0.084). At the second follow-up, the overall response rate was 58.3%, and the mean viral load level was 924.2 ± 493.7 RLU. γ-PGA may be helpful for the cytological regression and reduction of viral load in patients with high-risk HPV-positive VAIN, suggesting that γ-PGA is a promising treatment option for primary or persistent VAIN.

• 한국식품과학회지
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• 제48권2호
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• pp.153-158
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• 2016

혈행개선을 위한 나노전달시스템을 제조하기 위하여, 천연 양전하성 다당류인 키토산과 혈행개선 소재로 알려져 있는 푸코이단과 PGA을 이용하여 CS/Fu 및 CS/Fu/PGA 두 종류의 나노캡슐을 제조하였다. 기본 피복물질인 키토산의 농도가 증가됨에 따라 나노캡슐의 APTT의 증가로 내인성 혈액응고 활성은 증진되었으나 혈소판 응집능 또한 증가되는 경향을 나타냈다. 따라서 키토산 농도는 대조군과 혈소판 응집능이 유의적으로 차이가 나지 않으며 나노입자 제조가 가능한 최소 농도인 2 mg/mL로 고정하였다. 그 결과 CS/Fu 나노입자의 경우 푸코이단의 농도가 $5-20{\mu}g/mL$일 때 약 200 nm 크기의 입자가 균일하게 생성되었고, CS/Fu/PGA 나노입자의 경우 PGA의 농도 $1-10{\mu}g/mL$에서 약 100nm 크기의 입자가 균일하게 생성되었다. 푸코이단과 PGA 농도 증가에 따라서 나노캡슐의 내인성 혈액응고 활성은 증가되었으나, 혈소판 응집능에는 유의적 차이를 나타내지 않았다. 즉, CS/Fu과 CS/Fu/PGA 나노입자는 각각 약 200 nm와 100 nm의 작고 균일한 입자분포를 가지고 있으며, 내인성 혈액응고 활성을 나타내고 혈소판 응집능에 영향을 미치지 않기 때문에 향후 다양한 특성의 혈행개선 활성성분을 포집할 수 있는 나노전달체로써 활용될 수 있을 것으로 판단된다.

• 폴리머
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• 제31권2호
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• pp.168-176
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• 2007

라이소자임이 내포된 폴리감마글루탐산(PGA)의 서브-마이크론 크기의 미세입자를 압력, 온도, 노즐내경, 농도 등을 변화시켜가면서 초임계 반용매 침전법 (SAS)으로 제조하였다. SAS법의 전체적인 결과는 압력이 클수록, 온도가 낮을수록, 노즐 내경이 작을수록, 농도가 묽을수록 작은 입자가 얻어졌다. FT-IR로 분석한 결과, 본래 초기의 PGA:라이소자임:50 : 50의 조성비는 SAS 공정을 거치면서 최종 분말 입자 내에서는 33 : 67로 변화하였다. 이것은 PGA가 라이소자임보다 탄산가스/디메틸설폭사이드(DMSO) 혼합용매에 더 높은 용해도를 가지기 때문인 것으로 추측된다. 또 이러한 용해도 특성 때문에 생성 입자는 핵-껍질 구조를 갖고 있으며, 핵 부분은 라이소자임이 구성하는 것으로 여겨진다. 생성된 분말 입자 내에는 $7.8\times10^{-3}wt%$의 농도로 미량의 DMSO가 잔존하고 있음이 밝혀졌다.

• 한국기계가공학회지
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• 제13권3호
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• pp.35-41
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• 2014

Poly(g-glutamic acid) (g-PGA) is a very promising biodegradable polymer that is produced by microorganism of Bacillus subtilis. Because g-PGA is water-soluble, anionic, biodegradable, and even edible, its potential applications have been studied from an industrial standpoint. In this study, we fabricated porous g-PGA foams by means of a freeze-solvent extraction method for tissue-engineering applications. Porous g-PGA foams were chemically cross-linked using a hexamethylene diisocyanate solution. An aqueous basic solution was used to neutralize g-PGA foam for cell culturing. During an in vitro cell culture study, it was observed that primary rabbit ear chondrocytes were well at tached and spread over the surface oft hree-dimensional cross-linkedg-PGA foam. From these results, it is concluded that cross-linkedg-PGA foam is aprom is in gmaterial for tissue-engineering applications, especially those pertaining to the regeneration of human cartilage.

• Journal of Microbiology and Biotechnology
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• 제20권10호
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• pp.1424-1429
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• 2010

A poly(${\gamma}$-glutamic acid) (${\gamma}$PGA)-cholesterol conjugate was synthesized and its properties were then evaluated. The conjugate exhibited an amphiphilic nature derived from the hydrophilic ${\gamma}$PGA backbone and the hydrophobic cholesterol side chain. The conjugate spontaneously formed nanoparticles, becoming an aqueous solution when at low concentrations, and at high concentrations the result was the formation of a physical gel. By utilizing the self-aggregating properties of the conjugate in water, an artificial chaperone was developed. A complex of protein, with the nanoparticles of the conjugate, was formed and the protein was released upon the dissociation of the nanoparticles through the addition of ${\beta}$-cyclodextrin. For denatured carbonic anhydrase, the activity was recovered in the artificial chaperone of the nanoparticle conjugate.

• Food Science and Biotechnology
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• 제17권6호
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• pp.1279-1284
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• 2008

When cheonggukjgang was manufactured using a Bacillus subtilis CH10-1 starter culture, a short-term fermentation for 14-18 hr appeared to be the optimal for the raw cheonggukjang to avoid the formation of a bitter taste and to contain a high concentration of free sugars, whereas a long-term fermentation for more than 4 days was the optimal for the cheonggukjang for stew in order to contain a high concentration of free amino and organic acids, which are responsible for sweet, savory, and bitter tastes present in stewed cheonggukjang, During activation of murine splenic T cells with phytohemagglutinin (PHA), the presence of either poly-$\gamma$-glutamic acid ($\gamma$-PGA) or partially hydrolyzed $\gamma$-PGA resulted in reduction in the level of interferon-$\gamma$ production and enhancement in the level of interleukin-5 production, possibly due to suppression of Th1 activity and augmentation of Th2 activity. Taken together these results indicate that the raw cheonggukjang and the cheonggukjang for stew are different in their quality and taste as well as immunomodulating activity.

• Food Science and Biotechnology
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• 제16권4호
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• pp.509-514
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• 2007

In this study, we optimized the production of ${\gamma}-polyglutamic$ acid (PGA) in soybean milk cakes (SMC) fermented with Bacillus subtilis GT-D and B. subtilis KU-A, to be utilized as a functional food ingredient. PGA production was dependent upon the glutamate content, fermentation time, and type of Bacillus sp. The consistencies of the SMCs fermented by B. subtilis GT-D and B. subtilis KU-A were highest after 36 hr of fermentation, and then decreased gradually. The SMC fermented by B. subtilis KU-A had a higher consistency than the SMC fermented by B. subtilis GT-D. In the presence of 10% defatted soy flour (DFS), 5% glutamate in the SMC was efficiently converted into polyglutamic acid (PGA) for 24 hr, indicating a conversion yield above 96%, but its conversion then decreased with higher concentrations of glutamate. The soluble solid content (mucilage) of the SMC fermented with B. subtilis KU-A was 9.5%(w/w), and composed of 65.6% PGA (Mw 1,536 kDa) and some polysaccharides. However, the SMC fermented with B. subtilis GT-D had a mucilage content of 7.8%(w/w), and was composed of 66.4% PGA (Mw 1,409 kDa), 11.5% levan, and some polysaccharides. The viscoelastic values of the mucilage obtained using B. subtilis KU-A were much higher than those of mucilage obtained using B. subtilis GT-D. Also, the G'-value (elastic modulus) was higher than the G"-value (viscous modulus).